The present disclosure is related generally to filters for fluorescent lighting tubes. In particular, a removable sleeve for filtering various wavelengths of the electromagnetic spectrum emitted by fluorescent lights.
Fluorescent tubes produce light that creates little heat, consumes minimal power and provides an even distribution of illumination. In several areas of the lighting industry, it is often desirable to alter the color of the light produced by a fluorescent tube. Typically, plastic filters of various color coatings are used to accomplish these alterations.
Additionally, specific coatings can be added to the filter that blocks ultraviolet light produced by the fluorescent tube. Ultraviolet light can damage objects in a similar manner that sunlight damages skin. Blocking ultraviolet light produced by the fluorescent tube is especially desirable when lighting museum collections and other valuable objects.
Many different colors of a plastic or polyester film are available to alter the color of any lighting fixture including a fluorescent tube. See Apollo Design Technology's web page http://www.internetapollo.com/products/productline.aspx?pl_id=8. This flat translucent or transparent polymeric film, known to those familiar with the art, is called gel. This name most likely refers back to the early days of theater when a gelatin material was used to manufacture color filters for stage lighting.
One of the challenges encountered is how to attach a flat gel material to fluorescent lights, which are usually long, slender tubes of glass. Several products have been designed to aid in the process of adding colored gel to fluorescent tubes. See the product named “Super Tube” at www.gamonline.com by Great America Lighting. See also http://www.internetapollo.com/products/productline.aspx?pl_id=33 by Apollo Design Technology, Inc.
The drawback of the aforementioned products is that the fluorescent tube must be removed from the fixture in order to place the colored sleeve over the tube. This becomes a labor intensive when more than a few fixtures must be colored.
Another approach to adding color to fluorescent tubes is disclosed in U.S. Pat. No. 6,511,204, which discloses an elongated polycarbonate configured to fit over a fluorescent tube and sleeve adapted to receive a colored film sheet for altering the light output characteristics of the fluorescent tube. One drawback with this product is that a semi rigid polycarbonate tube must be clipped over the fluorescent lamp. Subjecting a long tube of thin glass to this additional pressure could create a safety issue during installation. Additionally, even greater pressures are added when the colored sleeve is removed from the fluorescent tube. This could lead to the tube falling to the floor or even shattering overhead.